1. Field of the Invention:
The invention relates to liquid propellant guns and more specifically to an injection system for a liquid propellant gun wherein the valve and injector cooperate such that the valve is able to contain high-pressure. This feature of the valve allows the bolt to be moved smoothly from projectile load to fire position without a forward jogging of the bolt after the fuel and oxidizer have been injected and before firing.
In the past it has been necessary, with liquid propellant guns featuring dynamic propellant loading, to protect the propellant injection valve from high breech pressure. This was accomplished by jogging the bolt forward past the valve port following injection such that a seal on the bolt nose held the breech pressure away from the valve. Bolt jog motion however, complicates the overall gun mechanism.
Three separate actuators are required in that the motion of each major component occurs sequentially; injection first, jog second, and bolt lock third. A subsequent operation cannot proceed until the previous operation has been completed.
Such a system would have difficulty achieving the short cycle time necessary for an automatic gun with a high rate of fire.
2. Description of the Prior Art:
Examples of prior art liquid propellant guns are set forth in U.S. Pat. Nos. 3,922,976 and 4,005,632. U.S. Pat. No. 3,992,976 especially focuses on the problem intended to be overcome in the present invention wherein after injection the bolt is moved forwardly thereby translating the projectile, propellant charge and bolt mechanism forwardly until the end of the bolt is ahead of the injector. The bolt mechanism must then be stopped and locked thereby locking the gun before firing. This protects the injector but the bolt actuation and locking system is complicated and must be heavy enough to withstand firing pressures. Also, power requirements are high and the rate of fire is reduced as a consequence of the stop-start action.